Apparatus for the cleaning of metal parts



Nov. 18, 1958 ZUCKER 2,860,646

APPARATUS FOR THE CLEANING OF METAL PARTS Filed March 29, 1955 2 Sheetg-Sheet l INVENTOR.

cmqws Quaker J. ZUCKER 2,860,546 APPARATUS FOR THE CLEANING OF METAL PARTS Nov. 18, 1958 2 Sheets-Sheet 2 Filed March 29, 1955 l m m m aw WW MM 3 Jw z m g M u m United States Patent APPARATUS FOR THE CLEANING 0F METAL PARTS The present invention relates to an apparatus for the cleaning of metal parts, particularly of loose material. It has already been proposed, to use chemical solvents e. g. trichloroethylene, perchloroethylene etc. for the removal of impurities on metal surfaces, as e. g. fat and oxide-layers. The effect of this degreasing method was considerably improved by the use of supersonic waves. Accordingly soiled parts were exposed to supersonic waves, which have the effect of detaching layers from the boundaiy surfaces and consequently have a cleaning effect. In the change from one particular medium to another the sound resistances at the boundary surfaces are different and at the resulting points of instability there arise more or less strong amplitudes of movement, whereupon the impurities are detached from the surface of the objects to be cleaned. However, the effect is only effective when the thickness of the object to be cleaned amounts to not quite a quarter of the wavelength or an uneven multiple of a quarter wavelength. At those places, where the said requirements do not apply, no cleaning can take place, because the surface of the object is not brought into movement.

Special difhculties occur during the cleaning of loose material as e. g. precision watch components etc. The loose material is, as is known, placed in a sieve basket and the latter dipped into a cleaning liquid, to which sound waves are then applied. The quantity of the loose material placed in the sieve basket is limited, so that only relatively little loose material can be cleaned at one time. If the thickness of the layer of loose material exceeds a certain amount then the supersonic waves no longer penetrate the layer, the items of loose material to be cleaned are not brought into motion and therefore are not cleaned.

It is an object of the invention to provide an improved apparatus for cleaning metal parts.

According to the invention therefore, I provide a process for the cleaning of metal parts, in particular of loose material characterised in that the parts to be cleaned are subjected to supersonic waves in a cleaning fluid, and during the treatment with supersonic waves a vacuum is produced in the treatment chamber. The maintenance of the vacuum assists the cleaning inasmuch as the gases in the liquid will be extracted from the pores of the particles, and the thus extracted gases will carry with them dirt particles which otherwise could not be removed from the pores.

It is furthermore of advantage if the parts to be cleaned are kept in motion mechanically in the cleaning fluid during the supersonic irradiation so that during the sound irradiation a loosening and a rearrangement of the layers of the parts to be cleaned takes place.

The apparatus suitable for carrying out the process according to the invention comprises a vibrator, which has a sieve basket for carrying the parts to be cleaned, which sieve basket is placed in a container, which has a device for the production of supersonic waves in the container.

2,860,646 Patented Nov. 18, 1958 Figs. 1 to 3 are diagrammatic views of three embodiments of an apparatus according to the invention for carrying out the process.

Referring to Fig. 1, 1 indicates a container, which serves to receive acleaning fluid e. g. trichloroethylene or water. On the bottom of the container 1 is a sound head 2 for producing supersonic waves. The loose material 3 to be cleaned is placed in a sieve basket 4, which is dipped in the cleaning fluid. The sieve basket is attached to a vibrator 5, which is supported on a stand 6.

For cleaning the loose material the latter is set into vibration together with basket 4 and simultaneously exposed to the supersonic waves. A constant loosening and rearrangement of the otherwise compact mass of loose material follows owing to the vibration, so that it is easily and intensely penetrated by the supersonic waves. Tests have shown that the resulting degree of cleaning is extraordinarily high and that the process can be carried out very uniformly.

A further improvement of the process described consists in that to improve the cleaning effect a vacuum and preferably a high vacuum, is used. Thus during the irradiation of the parts which are kept in motion mechanically a vacuum is produced in the processing chamber.

By the last described means, it is achieved that the individual particles of loose material not only experience a surface cleaning, but the otherwise blocked up pores of the particles are completely freed of fat and other impurities. Examination under the microscope of particles of loose material treated in the manner described shows, that the said particles have an entirely different surface character as opposed to particles, which have been treated in a like manner, but without a vacuum.

The apparatus according to Fig. 2 serves for producing the vacuum, it can be constructed similarly to the apparatus which is described and shown.

A container 1a, filled with a cleaning fluid e. g. water or trichloroethylene, and which has a sound head 2a on its bottom for the production of supersonic waves serves to receive the particles of loose material to be cleaned. The loose material 3a to be cleaned is placed in a sieve basket 4a which is dipped in the cleaning fluid. The container 10 is closed in an air tight manner by means of a lid 7. Furthermore, a suction pipe 8 with a closure valve 10 is provided which is connected to a high vacuum pump 9. A further pipe 11 opening into the container la communicates with the atmosphere and is closable by means of a valve 12. Finally a circulating conduit 13 is connected to the container 1a in which conduit 13 there is connected circulating pump 14, and a filter 15. 16 and 17 indicate valves by which the conduit 13 can be closed.

In operation the valve 10 is opened and the valves 12, 16 and 17 are closed. Thereafter the vacuum pump 9 is set in operation so that a vacuum of about 0.01 mm. is produced in the container 1a. At the: same time the material is subjected to the supersonic waves.

In order always to keep the treatment fluid clean, it is periodically passed through the conduit 13 in circulation and cleaned by filter 15. Finally the circulating pump 14 is switched off and the valves 16 and 17 are closed.

The process can also be used in conjunction with a known cleaning apparatus, in which the baskets are dipped in different baths one after another by a conveyor device. Such an arrangement is shown in Fig. 3.

The apparatus comprises a container 18 with a lateral opening 20 through which the containers: with loose material can be loaded and unloaded. In the container 18 conveyor rollers 19 are provided over which a conveyor chain 21 runs. The drive of the chains is effected in the usual manner and is not shown in the drawings. Carrier baskets 22, which are fixed to the conveyor chain by means of carrier arms 27 are provided to receive the loose material to be cleaned. The lower part of the container 18 has baths 23 in which the carrier baskets 22 are dipped one after another. In each bath 23 a sound head 24 is disposed for the'production of'supersonic vibrations. Furthermore a suction opening 25 is provided in each bath which is connected with a vacuum pump (not shown). In order to be able to produce a vacuum in chamber 26 each arm 27 is provided with a closure lid 28 which exactly fits the opening 29' of bath 23. For this purpose the opening is made conical.

In order to be able to clean the treatment fluid, inlet and outlet apertures 29 and 30 are provided in each bath which, similarly to the example according to Fig. 2 are connected to a circulating pipe with a circulating pump and filter.

The particles of loose material treated have an extraordinarily high degree of cleanliness and can be passed on for further treatment e. g. nickel plating, chromium plating, without any further treatment.

What I claim is:

1. Apparatus for the cleaning of metal parts comprising a container having a cover serving to close it in an air tight manner; means in the base of the container for producing supersonic waves in the container, said container having a circulating conduit connected thereto which conduit includes a circulating pump and a filter; and means communicating with said container for producing a vacuum therein.

2. A particle cleaning apparatus comprising, in combination, a receptacle defining a closed cleaning chamber adapted to receive a liquid; support means-for supporting in said cleaning chamber and under the level of a liquid received therewithin particles to be cleaned; generator means for producing supersonic waves in the liquid,

thereby subjecting to supersonic waves particles supported by said support means in said cleaning chamber below the liquid level of the liquid; and means communicating with .said cleaning chamber at a portion above" the liquid level for creating a vacuum in that portion of said cleaning chamber which is above the liquid level of the liquid.

3. A cleaning apparatus comprising, in combination, a receptacle defining a closed cleaning chamber adapted to receive therewithin a liquid so that when a liquid partly fills said cleaning chamber the same is divided by the liquid level into upper and lower portions; support means for supporting in said lower portion of said cleaning chamber particles to be cleaned; generator means arranged at the bottom of said receptacle and below particles supported by said support means for producing supersonic waves in the liquid in said lower portion, thereby subjecting the particles to supersonic waves; and means communicating with said upper portion of said cleaning chamber for creating a vacuum in said upper portion.

References Cited in the file of this patent UNITED STATES PATENTS 1,029,541 Haustetter June 11, 1912 1,508,828 Wholey Sept. 16, 1924 2,163,650 Weaver June 27, 1939 2,468,550 Fruth Apr. 26, 1949 2,495,295 Spanier Jan. 24, 1950 2,554,701 Hackett May 29, 1951 2,616,820 BourgeauX Nov. 4, 1952 2,702,260 Massa Feb. 15, 1955 V FOREIGN PATENTS 1,037,310 France Apr. 29, 1953 

